Plugin electric vehicle offer better fuel economy, lower emissions and good acceleration. Automotive manufacturers are introducing poly-in electric vehicles to the consumer market. At least one industry forecast predicts up to 400,000 battery electric vehicles in North America by the year 2020.
Quick chargers supply a connection to the grid for drivers on the go with a fast direct charge of electricity needed to refill the battery. A typical quick charger includes a rapid DC charging electric vehicle supply equipment housed in a free standing structure constructed of stainless steel or the like. At least some quick chargers operate with an input of (162 A @208V, 3 phase 3 wire 50/60 Hz) using a direct current flow (output 125 A@400 VDC and 50 KW maximum), to charge the electric vehicle's battery in 20-30 minutes typically connecting to the charger via a CHAdeMo compliant power connector or equivalent. The electric vehicle and the quick charger include safety checks to verify it is connected using 5 pins before DC power is available. The electric vehicles are also required to have an interlock deactivating the ignition while connected to the charger.
Gasoline and diesel pumps at filling stations are usually guarded with heavy duty posts called bollards which are typically painted bright yellow for high visibility and are located at each of the four corners of the fuel service islands and usually close to the pumps. These posts are generally at least four inches in diameter and are generally steel pipes which may concrete tilled or are constructed of steel reinforced concrete. These posts extend down into the foundation for increased strength. The purpose of the bollards is to prevent an out-of-control vehicle from striking a fuel pump and partially or totally dislodging the pump and cabinet from the foundation, at which point an explosion may occur due to the presence of leaking fuel and possible sparking of electrical wires. Furthermore, electrical wiring may be exposed and cause severe or lethal shocks to anyone in the adjacent area. However, bollards typically don't cover the entire area around the fuel pumps and an out-of-control vehicle approaching from a given angle is capable of dislodging a pump and causing the dangerous situation as described above. Further, bollards are sometimes installed incorrectly or may have been knocked loose and cannot provide protection as originally intended.
Additionally, with the advent of electrical cars and hybrid vehicles, EV or electrical vehicle charging stations are appearing in many location throughout the world. Many of these charging stations are similarly protected by bollards. And, as stated above, bollards don't totally prevent a vehicle from dislodging a charging station from a foundation. Obviously, such charging stations have high voltage wiring within the enclosure, generally entering from underground conduits within the foundation and going on up into the enclosure. These EV charging stations pose a possible more serious electrical hazard than do common fuel pumps. Consequently, serious danger is present when the charging station enclosure is dislodged and high voltage wiring is exposed.
There is a possibility of damage to an EV charging station or other high voltage system due to a collision or being struck with a force sufficient to cause component failure, physical damage, systemic damage, or physical displacement; damaging high winds resulting from natural occurrences such as hurricane, tornado, etc.; high water or flooding events; excessive/violent/sustained physical motion/movement/shaking such as an earthquake; physical damage resulting from vandalism or terroristic act; and/or a high heat beyond that which the system is capable of withstanding.
The damage may be sufficient to cause the enclosure, pole/post, or supporting structure to become completely dislodged from its foundation, mount, or supporting system; become partially dislodged from its foundation, mount, or supporting system; sustain physical damage; sustain damage to the components contained/housed/enclosed/supported; and/or overheat causing damage to the components contained/housed/enclosed/supported thereby.
Moreover, exposure of the dangerously high voltage power feed, and its' conductors, terminals, or wiring causing physical contact with conductive metals, liquids, or a person/animal creates the possibility for shock or electrocution and fire or explosion. Exposure of the dangerously high voltage power feed cabling, conductors, terminals, or wiring causing electrification by proximity to conductive metals, liquids, or person/animal could also create the possibility for shock or electrocution and fire or explosion.
In the event that a fuel pump or an EV charging station is exposed to a substantial enough force to move the pump on or from the originally mounted position on the foundation, a safety system should be in place to disconnect the incoming power at the source. Safety circuits which disconnect the incoming power in the event of a ground fault or in the event of a current overload are common in fuel pumping stations and EV charging stations. A ground fault or over current circuit might disconnect the incoming power to a dislodged station if the dislodging resulted in a ground fault or an over current situation, but it is possible that underground conduit may be broken and wiring exposed without creating a ground fault or and over current situation. The present invention, however, provides a safety circuit which disconnects incoming power when the station enclosure has become dislodged and has moved by at least a few thousandths of an inch, either horizontally or vertically, to remove the chance of electrical shocks or electrocution of bystanders who are unaware of such dangers.
Eaton Corporation, having a location in Cleveland, Ohio, USA, manufactures electric vehicle charging stations such as the POW-R-STATION LEVEL 2 and DC quick chargers (Electric Vehicle Supply Equipment (EVSE)), for the plug in electric vehicle industry. As set forth in Eaton's brochure and/or on-line (eaton.com) information, the power station electric vehicle charging stations supply the connection to the grid where vehicles park on the street, garage, or parking lot and provide the vehicle's onboard charge control circuit with energy to refill the battery. The 2 POW-R-STATION is designed for indoor or outdoor use and can be wall mounted for residential or commercial garage installations or can be free standing with a pedestal configuration. Usin: an industry standard J1772 30 A or 70 A connector, the charging station can fill a depleted all electric vehicle battery in as little as four hours. The driver simply connects the J1772 connector to the electric vehicle and the EV charging station determines the vehicle type and proper charging characteristics by providing a ‘wake-up’ signal through the connector. The charging system indicates the proper maximum line current (ALC) for that vehicle depending on the circuit size or the commands of a load management system and/or the requirements of the utility.